In battery systems used as driving sources for movable bodies such as electric automobiles or electric storage devices, a plurality of battery modules, which can be charged and discharged, are provided. Each of the battery modules has a configuration in which a plurality of batteries (battery cells) are connected in series, for example. The battery systems are provided with detection devices that detect abnormalities such as overcharge or overdischarge of the battery cells.
In an in-vehicle assembled battery control device discussed in Patent Document 1, a plurality of simplified cell overcharge/overdischarge detection devices are provided to correspond to a plurality of cell groups constituting an assembled battery. Each of the simplified cell overcharge/overdischarge detection devices determines whether a battery cell in the corresponding cell group is overcharged or overdischarged, and sends its result to a battery controller.
[Patent Document 1] JP 2003-79059 A